In this paper, we evaluate performance of model adaptation by the previously proposed HMM decomposition method[1] on telephone speech recognition. The HMM decomposition method separates a composed HMM into a known phoneme HMM and an unknown noise and channel HMM by maximum likelihood (ML) estimation of the HMM parameters. A transfer function (telephone channel) HMM is estimated using adaptation...

Sometimes called radio in the loop (RITL) or fixed-radio access (FRA), wireless local loop (WLL) is a system that connects subscribers to the public switched telephone network (PSTN) using radio signals as a substitute for copper for all or part of the connection between the subscriber and the switch. This includes cordless access systems, proprietary fixed radio access, and fixed cellular syst...

A 13-bit, 1.4-MS/s, sixth-order cascaded sigma–delta modulator oversampling at 16 X is implemented in a 0.72 m complementary metal–oxide–semiconductor process for use in the baseband path of a radio-frequency receiver. The modulator achieves 77 dB of dynamic range and dissipates 81 mW from a 3.3 V supply. It is characterized for the blocking and intermodulation requirements of a cordless teleph...

In this paper a novel frequency hopping algorithm is introduced, which is tailored for use in a Cordless Telephone System (CTS) that relies on total frequency hopping to use the same frequency band as a GSM system.The algorithm was designed with the goal of minimising the interference between different CTS-units and between the CTS and the overlay GSM network, taking into account standard GSM i...

This paper presents the use of PN junction diode on fractal monopole antenna with microstrip line for rreconfigurable multiband antennas. The developed multiband antennas focus on the applications for Wi-Fi, cordless telephone and satellite & radar. A fractal reconfigurable antenna was designed using the known fractal geometry such as Sierpinski gasket is fed by strip line using coaxial feed. A...

BACKGROUND Whether low-intensity radiofrequency radiation damages the blood-brain barrier has long been debated, but little or no consideration has been given to the blood-cerebrospinal fluid barrier. In this cross-sectional study we tested whether long-term and/or short-term use of wireless telephones was associated with changes in the serum transthyretin level, indicating altered transthyreti...

RE: " CELLULAR TELEPHONE USE AND RISK OF ACOUSTIC NEUROMA " Christensen et al. (1) recently presented results on the use of cellular telephones and the risk for acoustic neuroma. However, in our opinion, several issues need to be clarified in the paper. Our main concern is that the study did not take into account exposures from cordless phones, and associations specific for ever use of analog o...

BACKGROUND The exposure of young people to radiofrequency electromagnetic fields (RF-EMFs) has increased rapidly in recent years with their increased use of cellphones and use of cordless phones and WiFi. We sought to ascertain associations between New Zealand early-adolescents' subjective well-being and self-reported use of, or exposure to, wireless telephone and internet technology. METHODS...